Adjustable loop chain link wrench



Jan. 12, 1954 A. M. ROBERTSON ADJUSTABLELOOP CHAIN LINK WRENCH Filed Jan. 15, 1952 lvwsural a 01.3%};

Patented Jan. 12, 1954 ADJUSTABLE LO OP CHAIN LINK WRENCH Alexander Melvin Robertson, London, England Application January 15, 1952, Serial No. 266,480

Claims priority, application Great Britain January 18, 1951 4 Claims.

This invention concerns improvements relating to chain wrenches.

The object of the invention is to provide a chain wrench of simple and inexpensive construction.

The chain wrench according to the present invention comprises the combination of a handle, a length of chain for looping around the object to be turned, one end of the chain being fixed to the upper end of the handle, and a guide also on the upper end of the handle for slidably receiving the free end portion of the loop, whereby the chain can be drawn through the guide to tighten the loop about the object in preparation for turning of the object, the arrangement being such that, when the handle is pulled (or pushed) to turn the object with the chain loop drawn taut, the free end portion of the chain loop is automatically locked on the handle in or adjacent to the guide so as to hold the chain loop taut about the object.

In the preferred construction, the handle is substantially straight, the guide is in the form of an eye in the upper end of the handle set with its axis transverse to the handle, and the fixed end of the chain is secured to the handle above the eye.

The size of the eye is such as to permit small up-and-down and lateral movements of the chain therein.

The eye is preferably of rectangular section with a fiat top and a flat bottom. It may have an angular bottom edge at its entrant end, i. e. that end adjacent the chain loop.

The handle may conveniently be formed from a straight length of round section bar having its upper end flattened to form a head, which is pierced with an eye, and on top of the head is formed an integral lug to which the fixed end of the chain is secured, as by a pin or rivet.

One construction of chain wrench in accordance with the present invention will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 is a side elevation of the wrench;

Figure 2 is a front elevation of the wrench looking towards the left of Figure 1; and

Figure 3 is a fragmentary View, partly in section, of the upper end of the wrench, showing the chain in an alternative locking position.

Referring first to Figures 1 and 2, the wrench is provided with a straight solid handle ll) of circular cross-section. At its upper end the handle is flattened to form a head I l The opposite faces [2, I3 of the head are set in parallel. It will be seen from Figure 1 that one face l2 is in line with the wall of the handle, and that the other face is set in from the wall, being joined thereto by a shallow fillet I 4. The head is pierced with a hole It of rectangular section passing from one face to the other, i. e. with its axis transverse to the axis of the handle.

On top of the head is an integral lug I6. In the lug is fitted a pin H, on whose projecting ends are mounted two links at one end of a chain 19. The chain is shown fixed on the pin I? by a spring clip 20. Any other suitable means, such as a rivet, may be used for fixing the end of the chain to the lug IS.

The chain shown is the common sprocket chain, having links with concave side edges 2!.

The eye l5 in the head serves as a guide slidably to receive the free end portion of the chain l9. In size, the eye is such as to afford small upand-down and lateral clearance for the chain.

In Figure 1 the wrench is shown applied to a hexagon nut 22 ready for turning it. The chain is looped around the nut, and passed through the eye l5, and the short end 23 of the chain is pulled in order to draw the chain loop closely around the nut. The wrench [0 extends tangentially to the nut.

When the handle is grasped and pulled (or pushed) in the direction of the arrow, the nut is turned in an anti-clockwise direction. The pull on the handle causes an intermediate portion of the chain loop, i. e. that portion adjacent the eye, to be locked on the handle. At the same time the upper end of the handle above the eye tends to swing away from the nut so applying a tension to the chain loop and causing it to grip the nut.

In Figure 1 a pair of chain links is gripped between the nut and the face l3 beneath the eye, also one of said links, which links are of a length exceeding the thickness of the handle portion through which the hole It extends, is locked in the eye l5 by being set obliquely to the axis of the eye, so that the link is jammed between opposite walls of the eye. An alternative locking position for the free end of the chain loop is shown in Figure 3. Here a pair of chain links is set obliquely to each other in the eye. The upper ends of the two links bear against the roof of the eye, and the mid-portions of the links are supported by the bottom angular edge of the entrant end of the eye. In both positions it is found that the free end of the chain loop is securely locked on the handle to prevent expansion of the chain loop by withdrawal of chain through the eye when the chain is pulled (or pushed) to turn the nut.

Although the free end portion of the chain hangs down the handle, the operation of the wrench does not depend upon the chain being gripped by a hand against the handle.

The fillet I4 is also not essential to obtain the locking of the front end of the chain loop to the handle when the chain links are in the posi tion shown in Figure 1. The wrench will work equally well When the chain loop is arranged at the opposite face of the head.

To afiord a better grip of the chain around the part the links of the chain may have serrated edges to engage the part. Alternatively the chain may be fitted with one or more rubber bands or collars, or it may be covered by means of a rubber tube or rubber channel. The use of rubber is of importance when it is desired to prevent damage to the surface finish, such as plating, of the part.

I claim:

1. A chain wrench comprising a substantially straight handle, a chain having links, means fixing one end of the chain to one end of the han-- dle, the handle having a hole located adjacent to the fixed end of the chain and extending through the handle in a direction transverse thereto, the size of the hole being such as to permit the loose end portion of the chain being freely slidable with small clearance through the hole in both directions for contraction or expansion of a loop formed by the chain between the fixed end and the hole, each chain link exceeding in length the thickness of the handle portion through which said hole extends whereby with the chain loop contracted around an object it is locked against expansion by reason of the engagement of a link of the chain with two opposite walls of said hole and caused to grip an object when the handle is moved toward the chain loop about the point at which the handle joins the fixed end of the chain.

2, A chain wrench according to claim 1, wherein the hole is straight and is of constant crosssectional area throughout its length.

3. A chain wrench, comprising a substantially straight handle, a head on the handle, a lug on top of the head, a roller chain having links,

4' means fixing one end of the chain to the lug, the handle having a straight hole of rectangular section extending through the head in a direction transverse to the handle, the size of the hole being such as to permit the loose end portion of the chain being freely slidable with small clearance through the hole in both directions for expansion or contraction of a loop formed by the chain, each chain link exceeding in length the thickness of the handle portion through which said hole extends, whereby with the chain loop contracted around an object it is locked against expansion by reason of the engagement of a link of the chain with two opposite walls of said hole and caused to grip the object when the handle is moved toward the chain loop about the point at which the handle joins the fixed end of the chain.

4. A chain wrench comprising a straight handle, a head on the handle, said head having two opposite faces flat and parallel, a lug on top of the head, a roller chain having links, means fixing one end of the chain to the lug, the handle having a straight hole extending through the head from one flat face to the other in a direction transverse to the handle, the size of the hole being such as to receive the loose end portion of the chain with a small clearance all around, whereby the chain is freely slidable through the hole in both directions for expansion or contraction of a loop formed by the chain between the lug and the hole, each chain link exceeding in length the thickness of the handle por tion through which said hole extends, whereby with the chain loop contracted around an object it is locked against expansion of the chain by reason of the engagement of a link with two opposite walls of said hole and caused to grip an object when the handle is moved toward the chain loop about the point at which the handle joins the fixed end of the chain.

ALEXANDER MELVIN ROBERTSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 594,563 Ryrie Nov. 30, 1897 771,915 Meyer Oct. 11, 1904 1,104,146 Simpson July 21, 1914 

